cities={
    'puyang' : {'国家':"China", '人口': 8*10e5, 'fact': 'null', },
    '郑州' : {'国家':"China", '人口': 9*10e8, 'fact': 'null', },
    '洛杉矶' :{'国家':"America", '人口': 3*10e7, 'fact': 'null', },
}
for key,value in cities.items():
    print("城市：" + key + '的信息',end=":")
    for i in reversed(sorted(value.keys())):
        print(i+":"+str(value[i]),end=', ')
    print()

for key,value in cities.items():
    print("城市：" + key + '的信息',end=":")
   # for i in cities[key].keys():
   #     print(i+":"+cities['key'][i],end=', ')
    print()
